Eur. Phys. J. A (2017) 53: 233
https://doi.org/10.1140/epja/i2017-12431-2

Regular Article - Theoretical Physics

Revisiting directed flow in relativistic heavy-ion collisions from a multiphase transport model

¹ Shanghai Institute of Applied Physics, Chinese Academy of Sciences, 201800, Shanghai, China
² University of Chinese Academy of Sciences, 100049, Beijing, China

^* e-mail: xujun@sinap.ac.cn

Received: 14 June 2017
Accepted: 16 November 2017
Published online: 5 December 2017

Abstract

We have revisited several interesting questions on how the rapidity-odd directed flow is developed in relativistic ¹⁹⁷Au+¹⁹⁷Au collisions at and 39 GeV based on a multiphase transport model. As the partonic phase evolves with time, the slope of the parton directed flow at midrapidity region changes from negative to positive as a result of the later dynamics at 200 GeV, while it remains negative at 39 GeV due to the shorter life time of the partonic phase. The directed flow splitting for various quark species due to their different initial eccentricities is observed at 39 GeV, while the splitting is very small at 200GeV. From a dynamical coalescence algorithm with Wigner functions, we found that the directed flow of hadrons is a result of competition between the coalescence in momentum and coordinate space as well as further modifications by the hadronic rescatterings.